Merge the work on Generic Types Reification from 'dart-lang/reify' repo

pkg/kernel/lib/target/vmreify.dart

+// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+library kernel.target.vmreify;
+
+import '../ast.dart' show Program;
+import '../transformations/generic_types_reification.dart' as reify
+    show transformProgram;
+
+import 'targets.dart' show TargetFlags;
+import 'vmcc.dart' as vmcc_target;
+
+/// Specializes the kernel IR to the Dart VM with reified generic types.
+class VmGenericTypesReifiedTarget extends vmcc_target.VmClosureConvertedTarget {
+  VmGenericTypesReifiedTarget(TargetFlags flags) : super(flags);
+
+  @override
+  String get name => "vmreify";
+
+  // This is the order that bootstrap libraries are loaded according to
+  // `runtime/vm/object_store.h`.
+  List<String> get extraRequiredLibraries {
+    return new List<String>.from(super.extraRequiredLibraries)
+      ..add("${flags.kernelRuntime.resolve('reify/types.dart')}")
+      ..add("${flags.kernelRuntime.resolve('reify/declarations.dart')}")
+      ..add("${flags.kernelRuntime.resolve('reify/interceptors.dart')}");
+  }
+
+  @override
+  void performGlobalTransformations(Program program) {
+    super.performGlobalTransformations(program);
+    // TODO(dmitryas) this transformation should be made modular
+    reify.transformProgram(program);
+  }
+
+  // Disable tree shaking for Generic Types Reification. There are some runtime
+  // libraries that are required for the transformation and are shaken off,
+  // because they aren't invoked from the program being transformed prior to
+  // the transformation.
+  // TODO(dmitryas): remove this when the libraries are in dart:_internal
+  @override
+  void performTreeShaking(Program program) {}
+}